1 <?php
  2 
  3 namespace Docolight\Support;
  4 
  5 use Iterator;
  6 use CActiveRecord;
  7 
  8 /**
  9  * Iterate your active record in a page. Usefull to make a paging report.
 10  *
 11  * ```php
 12  *
 13  * $model = MyModel::model()->findByPk(1);
 14  *
 15  * $pager = new IterablePager($model, 20);
 16  *
 17  *
 18  * foreach($pager as $stack)
 19  * {
 20  *      // $stack = array with 20 length, contains MyModel implementation
 21  *      // next loop will be the next 20 and so on until the last of your
 22  *      // data. it respects your criteria also.
 23  * }
 24  * ```
 25  */
 26 abstract class IterablePager implements Iterator
 27 {
 28     /**
 29      * Total data.
 30      *
 31      * @var int
 32      */
 33     protected $total;
 34 
 35     /**
 36      * Current data.
 37      *
 38      * @var array
 39      */
 40     protected $current;
 41 
 42     /**
 43      * Model.
 44      *
 45      * @var CActiveRecord
 46      */
 47     protected $model;
 48 
 49     /**
 50      * Criteria.
 51      *
 52      * @var CDbCriteria
 53      */
 54     protected $criteria;
 55 
 56     /**
 57      * Class constructor.
 58      *
 59      * @param CActiveRecord $model
 60      * @param int           $limit
 61      */
 62     public function __construct(CActiveRecord $model, $limit = 10)
 63     {
 64         // Property assignment
 65         $this->model = $model;
 66         $this->criteria = clone $model->getDbCriteria();
 67 
 68         // Count data
 69         // Make sure it has no limit
 70         $this->criteria->limit = null;
 71         $model->setDbCriteria($this->criteria);
 72         $this->total = $model->count();
 73 
 74         // Start from zero
 75         $this->criteria->offset = 0;
 76 
 77         // Set limit
 78         $this->criteria->limit = $limit;
 79 
 80         // Set criteria
 81         $this->model->setDbCriteria($this->criteria);
 82 
 83         // Fetch first collection
 84         $this->current = $this->prepare($this->model->findAll($this->criteria));
 85     }
 86 
 87     /**
 88      * Rewind cursor.
 89      */
 90     public function rewind()
 91     {
 92         $this->criteria->offset = 0;
 93     }
 94 
 95     /**
 96      * Get current cursor.
 97      *
 98      * @return array
 99      */
100     public function current()
101     {
102         // Fetch new collection
103         $this->current = $this->prepare($this->model->findAll($this->criteria));
104 
105         return $this->current;
106     }
107 
108     /**
109      * Fetch next page.
110      */
111     public function next()
112     {
113         $this->criteria->offset = $this->criteria->offset + $this->criteria->limit;
114 
115         // Set new criteria of offset
116         $this->model->setDbCriteria($this->criteria);
117     }
118 
119     /**
120      * Determine whether next page exists.
121      *
122      * @return bool
123      */
124     public function valid()
125     {
126         return ($this->criteria->offset) <= ($this->total);
127     }
128 
129     /**
130      * Get current offset.
131      *
132      * @return int
133      */
134     public function key()
135     {
136         return $this->criteria->offset;
137     }
138 
139     /**
140      * Prepare the data before we store them in $current property.
141      *
142      * @param array $items
143      *
144      * @return mixed
145      */
146     abstract protected function prepare(array $items);
147 }
148